1. Field of the Invention
The present invention relates to a solar cell module which is easily fabricated, light in weight, low in price, and has excellent structural strength.
2. Related Background Art
In addition to research and development concerning solar cell elements per se, technological developments to make the solar cell elements available for use outdoors, for example, on the ground and on building roofs, have been conducted.
FIGS. 15 and 16 are sectional views schematically showing examples of two types of solar cell modules. Referring to FIGS. 15 and 16, a frame member 8 made of a material such as aluminum is provided at the periphery of solar cell modules 9 and 10, in order to reinforce the mechanical strength of the solar cell module and to mount it on a mounting stage.
The solar cell module illustrated in FIG. 15 employs a glass sheet 11 on its light receiving surface side and, on the back surface side, a film 12 having a moisture-resistant property such as a laminated film constituted of an aluminum film sandwiched between fluororesin films. In the solar cell modules, a solar cell element 13 or 17 is sealed by a translucent resin 14.
The solar cell module illustrated in FIG. 16 employs a fluororesin film 15 on its light receiving surface side and a metal reinforcement plate 16 on its back surface side. In this solar cell module, a solar cell element 17, for example, such as an amorphous silicon solar cell having a stainless substrate is sealed by a translucent resin 14. The solar cell module of this type does not require a glass member on the surface for preventing fracturing of the solar cell element 17 and protecting it, as the result of using a flexible cell element. Therefore, the solar cell module illustrated in FIG. 16 has an advantage in that it is possible to reduce the weight thereof compared to the module illustrated in FIG. 15 using the glass sheet 11.
As for the solar cell module of FIG. 16, a solar cell module of this type has been proposed in Japanese Patent Application Laid-open No. 5-337138, which does not use a frame member to secure its structural strength but is made as a box shape by bending its metal reinforcement plate 16 at four side portions so that it realizes sufficient structural strength as a module. Furthermore, this solar cell module does not comprise a frame member so that it is very useful in that it is light in weight and does not need a more complicated mounting step compared to the bending step.
When the solar cell module having such a solar cell element of a large area is fabricated, however, the following two problems are caused by the bending of its metal reinforcement member at the four side portions.